douglar wrote on 2026-01-07, 13:16:

Thanks! […]
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atar wrote on 2026-01-07, 10:27:

douglar wrote on 2026-01-07, 00:05:

Or do you have a read CF that you can test with to verify that the adapter works at all?

Hey, nice avatar. I use dosboot to boot NetBSD 😀. Do you mean to test it in 486 (because it works in i686, as in the original post)? Unfortunately I don't have any CF-cards and this is the question: are there any which support different voltages? And FWIW support different bus modes (16 bits vs. 32)?

Thanks!

Yes, it would be nice to test the 486 with a true CF if that was an option.

My experience is that most CompactFlash devices work at 5v and 3.3v, as dictated by the CF specification.

I hear that some of the really early CF devices and IBM micro drives performed better at 5v than at 3.3v.

The only device that I've ever run across that only worked at 3.3V looked like this--

The attachment Untitled.png is no longer available

Thought I'd add this https://imgur.com/a/sd-to-cf-adapter-cards-ma … piernov-6LfT5tS

weedeewee wrote on 2026-01-07, 17:22:

Thought I'd add this https://imgur.com/a/sd-to-cf-adapter-cards-ma … piernov-6LfT5tS

Mine identifies as 1.5. Also has the UDMA logo on it. I wonder if there's a change log for the revisions.

Bondi wrote on 2026-01-07, 16:26:

As for real CF cards, sure, almost all of them work fine in DOS, as long as they are 2gigs or less.

What happens if a card is larger than 2 Gigs? Can it be partitioned to have a first partition under 2G or it doesn't work at all?

atar wrote on 2026-01-07, 17:41:

weedeewee wrote on 2026-01-07, 17:22:

Thought I'd add this https://imgur.com/a/sd-to-cf-adapter-cards-ma … piernov-6LfT5tS

Mine identifies as 1.5. Also has the UDMA logo on it. I wonder if there's a change log for the revisions.

oh nice, you've got newer firmware 😀
I haven't gotten round to desoldering the eeprom and reading it out...
probably should've done that before putting it back together again.

I highly doubt there is any changelog for the firmware versions.

weedeewee wrote on 2026-01-07, 17:57:

oh nice, you've got newer firmware :-) I haven't gotten round to desoldering the eeprom and reading it out... probably should' […]
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atar wrote on 2026-01-07, 17:41:

Mine identifies as 1.5. Also has the UDMA logo on it. I wonder if there's a change log for the revisions.

oh nice, you've got newer firmware 😀
I haven't gotten round to desoldering the eeprom and reading it out...
probably should've done that before putting it back together again.

I highly doubt there is any changelog for the firmware versions.

I did some poking around and found this--
https://bitsavers.org/components/ktc/FC1307/firmware/

Edit --
FC-1307_2012_07_19-BANK_CF_V1.5B15.bin --> v1.2
FC-1307_2012_10_29-BANK_CF_V1.5B17.bin --> v1.3
FC-1307_2012_12_20-BANK_CF_V1.5B18.bin --> v1.4
FC-1307_2015_10_16-BANK_CF_V1.5B17.bin --> v1.5

Edit - Good reference
https://goughlui.com/2019/02/03/tested-generi … dapter-sd35vc0/

I have never had any luck with putting an SD->CF adapter inside things other than cameras.

I dont know why they never seem to work, but I've never had success.

Maybe a PCMCIA CF flash reader is sufficiently like a camera that it will work? Dunno, never tried.

I got some for use with a startech dual CF to IDE adapter for use in a vintage laptop, but no dice.

(I have a DSLR camera that they work in, and just decided to keep them in the camera box for that purpose.)

wierd_w wrote on 2026-01-07, 18:13:

I have never had any luck with putting an SD->CF adapter inside things other than cameras.

Good to know. Mine works like a charm in Thinkpad a30p. Haven't measured the performance, but at a first glance it's fast enough. If it had worked with 486 Laptop I would be happy with any speed.

douglar wrote on 2026-01-07, 18:09:

weedeewee wrote on 2026-01-07, 17:57:

oh nice, you've got newer firmware :-) I haven't gotten round to desoldering the eeprom and reading it out... probably should' […]
Show full quote

atar wrote on 2026-01-07, 17:41:

Mine identifies as 1.5. Also has the UDMA logo on it. I wonder if there's a change log for the revisions.

oh nice, you've got newer firmware 😀
I haven't gotten round to desoldering the eeprom and reading it out...
probably should've done that before putting it back together again.

I highly doubt there is any changelog for the firmware versions.

I did some poking around and found this--
https://bitsavers.org/components/ktc/FC1307/firmware/

Oh wow.... I only bought my card several years ago yet up in the parent directory is the schematic for such an adapter dated 2012.
Looking at the firmware files also makes me think the v1.5 firmware is from 2012, so from where did the chinese seller from which I bought it get the v1.3 firmware ?
oh well.
I think there exist also adapters that use an INIC-2051 chip. It's the one I first suspected of being in use before seeing the drive ID.
I opened them up to see if there was a voltage regulator inside, doesn't look like there is.

weedeewee wrote on 2026-01-07, 18:32:

Oh wow.... I only bought my card several years ago yet up in the parent directory is the schematic for such an adapter dated 201 […]
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Oh wow.... I only bought my card several years ago yet up in the parent directory is the schematic for such an adapter dated 2012.
Looking at the firmware files also makes me think the v1.5 firmware is from 2012, so from where did the chinese seller from which I bought it get the v1.3 firmware ?
oh well.
I think there exist also adapters that use an INIC-2051 chip. It's the one I first suspected of being in use before seeing the drive ID.
I opened them up to see if there was a voltage regulator inside, doesn't look like there is.

Poking though the binaries, I see:

FC-1307_2012_07_19-BANK_CF_V1.5B15.bin --> v1.2
FC-1307_2012_10_29-BANK_CF_V1.5B17.bin --> v1.3
FC-1307_2012_12_20-BANK_CF_V1.5B18.bin --> v1.4
FC-1307_2015_10_16-BANK_CF_V1.5B17.bin --> v1.5

douglar wrote on 2026-01-07, 18:36:

Poking though the binaries, I see: […]
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Poking though the binaries, I see:

FC-1307_2012_07_19-BANK_CF_V1.5B15.bin --> v1.2
FC-1307_2012_10_29-BANK_CF_V1.5B17.bin --> v1.3
FC-1307_2012_12_20-BANK_CF_V1.5B18.bin --> v1.4
FC-1307_2015_10_16-BANK_CF_V1.5B17.bin --> v1.5

There is a reddit post claiming that FC-1307_2015_10_16-BANK_CF_V1.5B17.bin makes it good enough for iPods. But since mine already identifies as 1.5 I guess I can't make it any better.

douglar wrote on 2026-01-07, 18:36:

Poking though the binaries, I see: […]
Show full quote

weedeewee wrote on 2026-01-07, 18:32:

Oh wow.... I only bought my card several years ago yet up in the parent directory is the schematic for such an adapter dated 201 […]
Show full quote

Oh wow.... I only bought my card several years ago yet up in the parent directory is the schematic for such an adapter dated 2012.
Looking at the firmware files also makes me think the v1.5 firmware is from 2012, so from where did the chinese seller from which I bought it get the v1.3 firmware ?
oh well.
I think there exist also adapters that use an INIC-2051 chip. It's the one I first suspected of being in use before seeing the drive ID.
I opened them up to see if there was a voltage regulator inside, doesn't look like there is.

Poking though the binaries, I see:

FC-1307_2012_07_19-BANK_CF_V1.5B15.bin --> v1.2
FC-1307_2012_10_29-BANK_CF_V1.5B17.bin --> v1.3
FC-1307_2012_12_20-BANK_CF_V1.5B18.bin --> v1.4
FC-1307_2015_10_16-BANK_CF_V1.5B17.bin --> v1.5

ok, thanks. That explains 😀

atar wrote on 2026-01-07, 17:55:

Bondi wrote on 2026-01-07, 16:26:

As for real CF cards, sure, almost all of them work fine in DOS, as long as they are 2gigs or less.

What happens if a card is larger than 2 Gigs? Can it be partitioned to have a first partition under 2G or it doesn't work at all?

I'm not sure, tbh. DOS 6.22 has the limitation of 2 gig per partition, 7.1 - doesn't. However pcmcia driver may have it's own limitation. I just don't have any cards bigger than 2Gb, so haven't tested myself. But other people report this limit.

Bondi wrote on 2026-01-07, 17:21:

I usually use IBM pcmcia drivers, which are default for Thinkpads. But Phoenix and Cardsoft work as well.
And, yes, pure cf cards+pcmcia adapter is actually the prefereed way to transfer files for many people 😀

I already ordered a couple of 2G CF cards, but while I'm waiting, to make it sure, these Thinkpads threy are pre pci, right? Because my CF-SD converter works on an i686 Thinkpad (a30p) too.

atar wrote on 2026-01-07, 19:17:

Bondi wrote on 2026-01-07, 17:21:

I usually use IBM pcmcia drivers, which are default for Thinkpads. But Phoenix and Cardsoft work as well.
And, yes, pure cf cards+pcmcia adapter is actually the prefereed way to transfer files for many people 😀

I already ordered a couple of 2G CF cards, but while I'm waiting, to make it sure, these Thinkpads threy are pre pci, right? Because my CF-SD converter works on an i686 Thinkpad (a30p) too.

Yes, it’s TP 360CE - 486-DX50 and 330C - 486SLC-50

Meanwhile some update. I was considering writing an ATAPI test program, and then it occurred to me that most probably someone had done it already. So I stumbled over ATACT.

And this great program can identify and read my SD card in the SD-CF adapter!

So the problem is definitely software, not hardware.
ATACT doesn't rely on card managers and programs the PCMCIA itself. So, the only question is how to do the same but mapping the card to a dos drive letter.

Have you tried with win95? I have a toshiba 486 laptop and use a pcmcia<->CFcard adapter and it works perfectly with w95. I know you only have 4Megs of RAM but win95 should still install and work (slowly, ehehe.)
The main problem I had was to convert the 256Mb CF card to behave like a hard drive, not a removable drive, but that's another story...

EduBat wrote on 2026-01-07, 20:28:

The main problem I had was to convert the 256Mb CF card to behave like a hard drive, not a removable drive, but that's another story...

Can your Toshiba boot from a pcmcia CF? It's likely newer then mine. I have BIOS 2.50 and there is no option to boot from pcmcia. Or, if not for booting, may I ask why did you convert it to behave like hdd?

I haven't tried W95 yet. Would need a larger HDD (or an IDE-CF) for that. Also I think there is virtually nothing launched from W95 which would make fun running on 4MiBs. Used to to it 30 years ago 😀 So W95 is gonna be the last resort if everything else fails.

Hi, no, I cannot boot from pcmcia cf.
Sorry for the confusion, I did not explain myself properly... I needed to convert to HDD because I also wanted to use the card with one of those passive IDE to CF adapters, not just in the pcmcia adapter.
I was just saying w95 because pcmcia works "out of the box". This way you could test your computer and be sure your pcmcia hardware works fine.

EduBat wrote on 2026-01-08, 18:03:

I was just saying w95 because pcmcia works "out of the box". This way you could test your computer and be sure your pcmcia hardware works fine.

Makes sense, indeed. Which version should I take? I sort of remember that the best w95 is w98se. So I've tried it. It installs, but fails a first start, looks like 4MiB is not enough for it (see the screen shot). Trying to boot it in safe mode now, and it's busy with something the last 30 minutes.

atar wrote on 2026-01-09, 15:38:

EduBat wrote on 2026-01-08, 18:03:

I was just saying w95 because pcmcia works "out of the box". This way you could test your computer and be sure your pcmcia hardware works fine.

Makes sense, indeed. Which version should I take? I sort of remember that the best w95 is w98se. So I've tried it. It installs, but fails a first start, looks like 4MiB is not enough for it (see the screen shot). Trying to boot it in safe mode now, and it's busy with something the last 30 minutes.

Off the top of my head---
Windows 95 RTM requires 4MB, but 16MB is recommended if you want to run W32 apps of the day, more if you are running newer programs.
Windows 95B (OSR2) requires 4MB, but installing is touch and go with less than 8MB
Windows 98 (RTM) requires 16MB, but want at least 24MB
Windows 98se requires 16MB, but now you probably want at least 32MB
Windows Me (Millennium Edition): requires 32MB but you probably want 128MB & a Pentium 2.